1 /* SPDX-License-Identifier: GPL-2.0 */
6 * Define 'struct task_struct' and provide the main scheduler
7 * APIs (schedule(), wakeup variants, etc.)
10 #include <uapi/linux/sched.h>
12 #include <asm/current.h>
14 #include <linux/pid.h>
15 #include <linux/sem.h>
16 #include <linux/shm.h>
17 #include <linux/kcov.h>
18 #include <linux/mutex.h>
19 #include <linux/plist.h>
20 #include <linux/hrtimer.h>
21 #include <linux/seccomp.h>
22 #include <linux/nodemask.h>
23 #include <linux/rcupdate.h>
24 #include <linux/refcount.h>
25 #include <linux/resource.h>
26 #include <linux/latencytop.h>
27 #include <linux/sched/prio.h>
28 #include <linux/signal_types.h>
29 #include <linux/mm_types_task.h>
30 #include <linux/task_io_accounting.h>
31 #include <linux/rseq.h>
33 /* task_struct member predeclarations (sorted alphabetically): */
35 struct backing_dev_info;
38 struct capture_control;
41 struct futex_pi_state;
46 struct perf_event_context;
48 struct pipe_inode_info;
51 struct robust_list_head;
57 struct sighand_struct;
59 struct task_delay_info;
63 * Task state bitmask. NOTE! These bits are also
64 * encoded in fs/proc/array.c: get_task_state().
66 * We have two separate sets of flags: task->state
67 * is about runnability, while task->exit_state are
68 * about the task exiting. Confusing, but this way
69 * modifying one set can't modify the other one by
73 /* Used in tsk->state: */
74 #define TASK_RUNNING 0x0000
75 #define TASK_INTERRUPTIBLE 0x0001
76 #define TASK_UNINTERRUPTIBLE 0x0002
77 #define __TASK_STOPPED 0x0004
78 #define __TASK_TRACED 0x0008
79 /* Used in tsk->exit_state: */
80 #define EXIT_DEAD 0x0010
81 #define EXIT_ZOMBIE 0x0020
82 #define EXIT_TRACE (EXIT_ZOMBIE | EXIT_DEAD)
83 /* Used in tsk->state again: */
84 #define TASK_PARKED 0x0040
85 #define TASK_DEAD 0x0080
86 #define TASK_WAKEKILL 0x0100
87 #define TASK_WAKING 0x0200
88 #define TASK_NOLOAD 0x0400
89 #define TASK_NEW 0x0800
90 #define TASK_STATE_MAX 0x1000
92 /* Convenience macros for the sake of set_current_state: */
93 #define TASK_KILLABLE (TASK_WAKEKILL | TASK_UNINTERRUPTIBLE)
94 #define TASK_STOPPED (TASK_WAKEKILL | __TASK_STOPPED)
95 #define TASK_TRACED (TASK_WAKEKILL | __TASK_TRACED)
97 #define TASK_IDLE (TASK_UNINTERRUPTIBLE | TASK_NOLOAD)
99 /* Convenience macros for the sake of wake_up(): */
100 #define TASK_NORMAL (TASK_INTERRUPTIBLE | TASK_UNINTERRUPTIBLE)
102 /* get_task_state(): */
103 #define TASK_REPORT (TASK_RUNNING | TASK_INTERRUPTIBLE | \
104 TASK_UNINTERRUPTIBLE | __TASK_STOPPED | \
105 __TASK_TRACED | EXIT_DEAD | EXIT_ZOMBIE | \
108 #define task_is_traced(task) ((task->state & __TASK_TRACED) != 0)
110 #define task_is_stopped(task) ((task->state & __TASK_STOPPED) != 0)
112 #define task_is_stopped_or_traced(task) ((task->state & (__TASK_STOPPED | __TASK_TRACED)) != 0)
114 #define task_contributes_to_load(task) ((task->state & TASK_UNINTERRUPTIBLE) != 0 && \
115 (task->flags & PF_FROZEN) == 0 && \
116 (task->state & TASK_NOLOAD) == 0)
118 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
121 * Special states are those that do not use the normal wait-loop pattern. See
122 * the comment with set_special_state().
124 #define is_special_task_state(state) \
125 ((state) & (__TASK_STOPPED | __TASK_TRACED | TASK_PARKED | TASK_DEAD))
127 #define __set_current_state(state_value) \
129 WARN_ON_ONCE(is_special_task_state(state_value));\
130 current->task_state_change = _THIS_IP_; \
131 current->state = (state_value); \
134 #define set_current_state(state_value) \
136 WARN_ON_ONCE(is_special_task_state(state_value));\
137 current->task_state_change = _THIS_IP_; \
138 smp_store_mb(current->state, (state_value)); \
141 #define set_special_state(state_value) \
143 unsigned long flags; /* may shadow */ \
144 WARN_ON_ONCE(!is_special_task_state(state_value)); \
145 raw_spin_lock_irqsave(¤t->pi_lock, flags); \
146 current->task_state_change = _THIS_IP_; \
147 current->state = (state_value); \
148 raw_spin_unlock_irqrestore(¤t->pi_lock, flags); \
152 * set_current_state() includes a barrier so that the write of current->state
153 * is correctly serialised wrt the caller's subsequent test of whether to
157 * set_current_state(TASK_UNINTERRUPTIBLE);
163 * __set_current_state(TASK_RUNNING);
165 * If the caller does not need such serialisation (because, for instance, the
166 * condition test and condition change and wakeup are under the same lock) then
167 * use __set_current_state().
169 * The above is typically ordered against the wakeup, which does:
171 * need_sleep = false;
172 * wake_up_state(p, TASK_UNINTERRUPTIBLE);
174 * where wake_up_state() executes a full memory barrier before accessing the
177 * Wakeup will do: if (@state & p->state) p->state = TASK_RUNNING, that is,
178 * once it observes the TASK_UNINTERRUPTIBLE store the waking CPU can issue a
179 * TASK_RUNNING store which can collide with __set_current_state(TASK_RUNNING).
181 * However, with slightly different timing the wakeup TASK_RUNNING store can
182 * also collide with the TASK_UNINTERRUPTIBLE store. Losing that store is not
183 * a problem either because that will result in one extra go around the loop
184 * and our @cond test will save the day.
186 * Also see the comments of try_to_wake_up().
188 #define __set_current_state(state_value) \
189 current->state = (state_value)
191 #define set_current_state(state_value) \
192 smp_store_mb(current->state, (state_value))
195 * set_special_state() should be used for those states when the blocking task
196 * can not use the regular condition based wait-loop. In that case we must
197 * serialize against wakeups such that any possible in-flight TASK_RUNNING stores
198 * will not collide with our state change.
200 #define set_special_state(state_value) \
202 unsigned long flags; /* may shadow */ \
203 raw_spin_lock_irqsave(¤t->pi_lock, flags); \
204 current->state = (state_value); \
205 raw_spin_unlock_irqrestore(¤t->pi_lock, flags); \
210 /* Task command name length: */
211 #define TASK_COMM_LEN 16
213 extern void scheduler_tick(void);
215 #define MAX_SCHEDULE_TIMEOUT LONG_MAX
217 extern long schedule_timeout(long timeout);
218 extern long schedule_timeout_interruptible(long timeout);
219 extern long schedule_timeout_killable(long timeout);
220 extern long schedule_timeout_uninterruptible(long timeout);
221 extern long schedule_timeout_idle(long timeout);
222 asmlinkage void schedule(void);
223 extern void schedule_preempt_disabled(void);
225 extern int __must_check io_schedule_prepare(void);
226 extern void io_schedule_finish(int token);
227 extern long io_schedule_timeout(long timeout);
228 extern void io_schedule(void);
231 * struct prev_cputime - snapshot of system and user cputime
232 * @utime: time spent in user mode
233 * @stime: time spent in system mode
234 * @lock: protects the above two fields
236 * Stores previous user/system time values such that we can guarantee
239 struct prev_cputime {
240 #ifndef CONFIG_VIRT_CPU_ACCOUNTING_NATIVE
248 * struct task_cputime - collected CPU time counts
249 * @utime: time spent in user mode, in nanoseconds
250 * @stime: time spent in kernel mode, in nanoseconds
251 * @sum_exec_runtime: total time spent on the CPU, in nanoseconds
253 * This structure groups together three kinds of CPU time that are tracked for
254 * threads and thread groups. Most things considering CPU time want to group
255 * these counts together and treat all three of them in parallel.
257 struct task_cputime {
260 unsigned long long sum_exec_runtime;
263 /* Alternate field names when used on cache expirations: */
264 #define virt_exp utime
265 #define prof_exp stime
266 #define sched_exp sum_exec_runtime
269 /* Task is sleeping or running in a CPU with VTIME inactive: */
271 /* Task runs in userspace in a CPU with VTIME active: */
273 /* Task runs in kernelspace in a CPU with VTIME active: */
279 unsigned long long starttime;
280 enum vtime_state state;
287 * Utilization clamp constraints.
288 * @UCLAMP_MIN: Minimum utilization
289 * @UCLAMP_MAX: Maximum utilization
290 * @UCLAMP_CNT: Utilization clamp constraints count
299 #ifdef CONFIG_SCHED_INFO
300 /* Cumulative counters: */
302 /* # of times we have run on this CPU: */
303 unsigned long pcount;
305 /* Time spent waiting on a runqueue: */
306 unsigned long long run_delay;
310 /* When did we last run on a CPU? */
311 unsigned long long last_arrival;
313 /* When were we last queued to run? */
314 unsigned long long last_queued;
316 #endif /* CONFIG_SCHED_INFO */
320 * Integer metrics need fixed point arithmetic, e.g., sched/fair
321 * has a few: load, load_avg, util_avg, freq, and capacity.
323 * We define a basic fixed point arithmetic range, and then formalize
324 * all these metrics based on that basic range.
326 # define SCHED_FIXEDPOINT_SHIFT 10
327 # define SCHED_FIXEDPOINT_SCALE (1L << SCHED_FIXEDPOINT_SHIFT)
329 /* Increase resolution of cpu_capacity calculations */
330 # define SCHED_CAPACITY_SHIFT SCHED_FIXEDPOINT_SHIFT
331 # define SCHED_CAPACITY_SCALE (1L << SCHED_CAPACITY_SHIFT)
334 unsigned long weight;
339 * struct util_est - Estimation utilization of FAIR tasks
340 * @enqueued: instantaneous estimated utilization of a task/cpu
341 * @ewma: the Exponential Weighted Moving Average (EWMA)
342 * utilization of a task
344 * Support data structure to track an Exponential Weighted Moving Average
345 * (EWMA) of a FAIR task's utilization. New samples are added to the moving
346 * average each time a task completes an activation. Sample's weight is chosen
347 * so that the EWMA will be relatively insensitive to transient changes to the
350 * The enqueued attribute has a slightly different meaning for tasks and cpus:
351 * - task: the task's util_avg at last task dequeue time
352 * - cfs_rq: the sum of util_est.enqueued for each RUNNABLE task on that CPU
353 * Thus, the util_est.enqueued of a task represents the contribution on the
354 * estimated utilization of the CPU where that task is currently enqueued.
356 * Only for tasks we track a moving average of the past instantaneous
357 * estimated utilization. This allows to absorb sporadic drops in utilization
358 * of an otherwise almost periodic task.
361 unsigned int enqueued;
363 #define UTIL_EST_WEIGHT_SHIFT 2
364 } __attribute__((__aligned__(sizeof(u64))));
367 * The load_avg/util_avg accumulates an infinite geometric series
368 * (see __update_load_avg() in kernel/sched/fair.c).
370 * [load_avg definition]
372 * load_avg = runnable% * scale_load_down(load)
374 * where runnable% is the time ratio that a sched_entity is runnable.
375 * For cfs_rq, it is the aggregated load_avg of all runnable and
376 * blocked sched_entities.
378 * [util_avg definition]
380 * util_avg = running% * SCHED_CAPACITY_SCALE
382 * where running% is the time ratio that a sched_entity is running on
383 * a CPU. For cfs_rq, it is the aggregated util_avg of all runnable
384 * and blocked sched_entities.
386 * load_avg and util_avg don't direcly factor frequency scaling and CPU
387 * capacity scaling. The scaling is done through the rq_clock_pelt that
388 * is used for computing those signals (see update_rq_clock_pelt())
390 * N.B., the above ratios (runnable% and running%) themselves are in the
391 * range of [0, 1]. To do fixed point arithmetics, we therefore scale them
392 * to as large a range as necessary. This is for example reflected by
393 * util_avg's SCHED_CAPACITY_SCALE.
397 * The 64-bit load_sum can have 4353082796 (=2^64/47742/88761) entities
398 * with the highest load (=88761), always runnable on a single cfs_rq,
399 * and should not overflow as the number already hits PID_MAX_LIMIT.
401 * For all other cases (including 32-bit kernels), struct load_weight's
402 * weight will overflow first before we do, because:
404 * Max(load_avg) <= Max(load.weight)
406 * Then it is the load_weight's responsibility to consider overflow
410 u64 last_update_time;
412 u64 runnable_load_sum;
415 unsigned long load_avg;
416 unsigned long runnable_load_avg;
417 unsigned long util_avg;
418 struct util_est util_est;
419 } ____cacheline_aligned;
421 struct sched_statistics {
422 #ifdef CONFIG_SCHEDSTATS
432 s64 sum_sleep_runtime;
439 u64 nr_migrations_cold;
440 u64 nr_failed_migrations_affine;
441 u64 nr_failed_migrations_running;
442 u64 nr_failed_migrations_hot;
443 u64 nr_forced_migrations;
447 u64 nr_wakeups_migrate;
448 u64 nr_wakeups_local;
449 u64 nr_wakeups_remote;
450 u64 nr_wakeups_affine;
451 u64 nr_wakeups_affine_attempts;
452 u64 nr_wakeups_passive;
457 struct sched_entity {
458 /* For load-balancing: */
459 struct load_weight load;
460 unsigned long runnable_weight;
461 struct rb_node run_node;
462 struct list_head group_node;
466 u64 sum_exec_runtime;
468 u64 prev_sum_exec_runtime;
472 struct sched_statistics statistics;
474 #ifdef CONFIG_FAIR_GROUP_SCHED
476 struct sched_entity *parent;
477 /* rq on which this entity is (to be) queued: */
478 struct cfs_rq *cfs_rq;
479 /* rq "owned" by this entity/group: */
485 * Per entity load average tracking.
487 * Put into separate cache line so it does not
488 * collide with read-mostly values above.
490 struct sched_avg avg;
494 struct sched_rt_entity {
495 struct list_head run_list;
496 unsigned long timeout;
497 unsigned long watchdog_stamp;
498 unsigned int time_slice;
499 unsigned short on_rq;
500 unsigned short on_list;
502 struct sched_rt_entity *back;
503 #ifdef CONFIG_RT_GROUP_SCHED
504 struct sched_rt_entity *parent;
505 /* rq on which this entity is (to be) queued: */
507 /* rq "owned" by this entity/group: */
510 } __randomize_layout;
512 struct sched_dl_entity {
513 struct rb_node rb_node;
516 * Original scheduling parameters. Copied here from sched_attr
517 * during sched_setattr(), they will remain the same until
518 * the next sched_setattr().
520 u64 dl_runtime; /* Maximum runtime for each instance */
521 u64 dl_deadline; /* Relative deadline of each instance */
522 u64 dl_period; /* Separation of two instances (period) */
523 u64 dl_bw; /* dl_runtime / dl_period */
524 u64 dl_density; /* dl_runtime / dl_deadline */
527 * Actual scheduling parameters. Initialized with the values above,
528 * they are continuously updated during task execution. Note that
529 * the remaining runtime could be < 0 in case we are in overrun.
531 s64 runtime; /* Remaining runtime for this instance */
532 u64 deadline; /* Absolute deadline for this instance */
533 unsigned int flags; /* Specifying the scheduler behaviour */
538 * @dl_throttled tells if we exhausted the runtime. If so, the
539 * task has to wait for a replenishment to be performed at the
540 * next firing of dl_timer.
542 * @dl_boosted tells if we are boosted due to DI. If so we are
543 * outside bandwidth enforcement mechanism (but only until we
544 * exit the critical section);
546 * @dl_yielded tells if task gave up the CPU before consuming
547 * all its available runtime during the last job.
549 * @dl_non_contending tells if the task is inactive while still
550 * contributing to the active utilization. In other words, it
551 * indicates if the inactive timer has been armed and its handler
552 * has not been executed yet. This flag is useful to avoid race
553 * conditions between the inactive timer handler and the wakeup
556 * @dl_overrun tells if the task asked to be informed about runtime
559 unsigned int dl_throttled : 1;
560 unsigned int dl_boosted : 1;
561 unsigned int dl_yielded : 1;
562 unsigned int dl_non_contending : 1;
563 unsigned int dl_overrun : 1;
566 * Bandwidth enforcement timer. Each -deadline task has its
567 * own bandwidth to be enforced, thus we need one timer per task.
569 struct hrtimer dl_timer;
572 * Inactive timer, responsible for decreasing the active utilization
573 * at the "0-lag time". When a -deadline task blocks, it contributes
574 * to GRUB's active utilization until the "0-lag time", hence a
575 * timer is needed to decrease the active utilization at the correct
578 struct hrtimer inactive_timer;
581 #ifdef CONFIG_UCLAMP_TASK
582 /* Number of utilization clamp buckets (shorter alias) */
583 #define UCLAMP_BUCKETS CONFIG_UCLAMP_BUCKETS_COUNT
586 * Utilization clamp for a scheduling entity
587 * @value: clamp value "assigned" to a se
588 * @bucket_id: bucket index corresponding to the "assigned" value
589 * @active: the se is currently refcounted in a rq's bucket
590 * @user_defined: the requested clamp value comes from user-space
592 * The bucket_id is the index of the clamp bucket matching the clamp value
593 * which is pre-computed and stored to avoid expensive integer divisions from
596 * The active bit is set whenever a task has got an "effective" value assigned,
597 * which can be different from the clamp value "requested" from user-space.
598 * This allows to know a task is refcounted in the rq's bucket corresponding
599 * to the "effective" bucket_id.
601 * The user_defined bit is set whenever a task has got a task-specific clamp
602 * value requested from userspace, i.e. the system defaults apply to this task
603 * just as a restriction. This allows to relax default clamps when a less
604 * restrictive task-specific value has been requested, thus allowing to
605 * implement a "nice" semantic. For example, a task running with a 20%
606 * default boost can still drop its own boosting to 0%.
609 unsigned int value : bits_per(SCHED_CAPACITY_SCALE);
610 unsigned int bucket_id : bits_per(UCLAMP_BUCKETS);
611 unsigned int active : 1;
612 unsigned int user_defined : 1;
614 #endif /* CONFIG_UCLAMP_TASK */
620 u8 exp_hint; /* Hint for performance. */
623 u32 s; /* Set of bits. */
626 enum perf_event_task_context {
627 perf_invalid_context = -1,
630 perf_nr_task_contexts,
634 struct wake_q_node *next;
638 #ifdef CONFIG_THREAD_INFO_IN_TASK
640 * For reasons of header soup (see current_thread_info()), this
641 * must be the first element of task_struct.
643 struct thread_info thread_info;
645 /* -1 unrunnable, 0 runnable, >0 stopped: */
649 * This begins the randomizable portion of task_struct. Only
650 * scheduling-critical items should be added above here.
652 randomized_struct_fields_start
656 /* Per task flags (PF_*), defined further below: */
661 struct llist_node wake_entry;
663 #ifdef CONFIG_THREAD_INFO_IN_TASK
667 unsigned int wakee_flips;
668 unsigned long wakee_flip_decay_ts;
669 struct task_struct *last_wakee;
672 * recent_used_cpu is initially set as the last CPU used by a task
673 * that wakes affine another task. Waker/wakee relationships can
674 * push tasks around a CPU where each wakeup moves to the next one.
675 * Tracking a recently used CPU allows a quick search for a recently
676 * used CPU that may be idle.
686 unsigned int rt_priority;
688 const struct sched_class *sched_class;
689 struct sched_entity se;
690 struct sched_rt_entity rt;
691 #ifdef CONFIG_CGROUP_SCHED
692 struct task_group *sched_task_group;
694 struct sched_dl_entity dl;
696 #ifdef CONFIG_UCLAMP_TASK
697 /* Clamp values requested for a scheduling entity */
698 struct uclamp_se uclamp_req[UCLAMP_CNT];
699 /* Effective clamp values used for a scheduling entity */
700 struct uclamp_se uclamp[UCLAMP_CNT];
703 #ifdef CONFIG_PREEMPT_NOTIFIERS
704 /* List of struct preempt_notifier: */
705 struct hlist_head preempt_notifiers;
708 #ifdef CONFIG_BLK_DEV_IO_TRACE
709 unsigned int btrace_seq;
714 const cpumask_t *cpus_ptr;
717 #ifdef CONFIG_PREEMPT_RCU
718 int rcu_read_lock_nesting;
719 union rcu_special rcu_read_unlock_special;
720 struct list_head rcu_node_entry;
721 struct rcu_node *rcu_blocked_node;
722 #endif /* #ifdef CONFIG_PREEMPT_RCU */
724 #ifdef CONFIG_TASKS_RCU
725 unsigned long rcu_tasks_nvcsw;
726 u8 rcu_tasks_holdout;
728 int rcu_tasks_idle_cpu;
729 struct list_head rcu_tasks_holdout_list;
730 #endif /* #ifdef CONFIG_TASKS_RCU */
732 struct sched_info sched_info;
734 struct list_head tasks;
736 struct plist_node pushable_tasks;
737 struct rb_node pushable_dl_tasks;
740 struct mm_struct *mm;
741 struct mm_struct *active_mm;
743 /* Per-thread vma caching: */
744 struct vmacache vmacache;
746 #ifdef SPLIT_RSS_COUNTING
747 struct task_rss_stat rss_stat;
752 /* The signal sent when the parent dies: */
754 /* JOBCTL_*, siglock protected: */
755 unsigned long jobctl;
757 /* Used for emulating ABI behavior of previous Linux versions: */
758 unsigned int personality;
760 /* Scheduler bits, serialized by scheduler locks: */
761 unsigned sched_reset_on_fork:1;
762 unsigned sched_contributes_to_load:1;
763 unsigned sched_migrated:1;
764 unsigned sched_remote_wakeup:1;
766 unsigned sched_psi_wake_requeue:1;
769 /* Force alignment to the next boundary: */
772 /* Unserialized, strictly 'current' */
774 /* Bit to tell LSMs we're in execve(): */
775 unsigned in_execve:1;
776 unsigned in_iowait:1;
777 #ifndef TIF_RESTORE_SIGMASK
778 unsigned restore_sigmask:1;
781 unsigned in_user_fault:1;
783 #ifdef CONFIG_COMPAT_BRK
784 unsigned brk_randomized:1;
786 #ifdef CONFIG_CGROUPS
787 /* disallow userland-initiated cgroup migration */
788 unsigned no_cgroup_migration:1;
789 /* task is frozen/stopped (used by the cgroup freezer) */
792 #ifdef CONFIG_BLK_CGROUP
793 /* to be used once the psi infrastructure lands upstream. */
794 unsigned use_memdelay:1;
797 unsigned long atomic_flags; /* Flags requiring atomic access. */
799 struct restart_block restart_block;
804 #ifdef CONFIG_STACKPROTECTOR
805 /* Canary value for the -fstack-protector GCC feature: */
806 unsigned long stack_canary;
809 * Pointers to the (original) parent process, youngest child, younger sibling,
810 * older sibling, respectively. (p->father can be replaced with
811 * p->real_parent->pid)
814 /* Real parent process: */
815 struct task_struct __rcu *real_parent;
817 /* Recipient of SIGCHLD, wait4() reports: */
818 struct task_struct __rcu *parent;
821 * Children/sibling form the list of natural children:
823 struct list_head children;
824 struct list_head sibling;
825 struct task_struct *group_leader;
828 * 'ptraced' is the list of tasks this task is using ptrace() on.
830 * This includes both natural children and PTRACE_ATTACH targets.
831 * 'ptrace_entry' is this task's link on the p->parent->ptraced list.
833 struct list_head ptraced;
834 struct list_head ptrace_entry;
836 /* PID/PID hash table linkage. */
837 struct pid *thread_pid;
838 struct hlist_node pid_links[PIDTYPE_MAX];
839 struct list_head thread_group;
840 struct list_head thread_node;
842 struct completion *vfork_done;
844 /* CLONE_CHILD_SETTID: */
845 int __user *set_child_tid;
847 /* CLONE_CHILD_CLEARTID: */
848 int __user *clear_child_tid;
852 #ifdef CONFIG_ARCH_HAS_SCALED_CPUTIME
857 struct prev_cputime prev_cputime;
858 #ifdef CONFIG_VIRT_CPU_ACCOUNTING_GEN
862 #ifdef CONFIG_NO_HZ_FULL
863 atomic_t tick_dep_mask;
865 /* Context switch counts: */
867 unsigned long nivcsw;
869 /* Monotonic time in nsecs: */
872 /* Boot based time in nsecs: */
875 /* MM fault and swap info: this can arguably be seen as either mm-specific or thread-specific: */
876 unsigned long min_flt;
877 unsigned long maj_flt;
879 #ifdef CONFIG_POSIX_TIMERS
880 struct task_cputime cputime_expires;
881 struct list_head cpu_timers[3];
884 /* Process credentials: */
886 /* Tracer's credentials at attach: */
887 const struct cred __rcu *ptracer_cred;
889 /* Objective and real subjective task credentials (COW): */
890 const struct cred __rcu *real_cred;
892 /* Effective (overridable) subjective task credentials (COW): */
893 const struct cred __rcu *cred;
896 * executable name, excluding path.
898 * - normally initialized setup_new_exec()
899 * - access it with [gs]et_task_comm()
900 * - lock it with task_lock()
902 char comm[TASK_COMM_LEN];
904 struct nameidata *nameidata;
906 #ifdef CONFIG_SYSVIPC
907 struct sysv_sem sysvsem;
908 struct sysv_shm sysvshm;
910 #ifdef CONFIG_DETECT_HUNG_TASK
911 unsigned long last_switch_count;
912 unsigned long last_switch_time;
914 /* Filesystem information: */
915 struct fs_struct *fs;
917 /* Open file information: */
918 struct files_struct *files;
921 struct nsproxy *nsproxy;
923 /* Signal handlers: */
924 struct signal_struct *signal;
925 struct sighand_struct *sighand;
927 sigset_t real_blocked;
928 /* Restored if set_restore_sigmask() was used: */
929 sigset_t saved_sigmask;
930 struct sigpending pending;
931 unsigned long sas_ss_sp;
933 unsigned int sas_ss_flags;
935 struct callback_head *task_works;
938 #ifdef CONFIG_AUDITSYSCALL
939 struct audit_context *audit_context;
942 unsigned int sessionid;
944 struct seccomp seccomp;
946 /* Thread group tracking: */
950 /* Protection against (de-)allocation: mm, files, fs, tty, keyrings, mems_allowed, mempolicy: */
951 spinlock_t alloc_lock;
953 /* Protection of the PI data structures: */
954 raw_spinlock_t pi_lock;
956 struct wake_q_node wake_q;
958 #ifdef CONFIG_RT_MUTEXES
959 /* PI waiters blocked on a rt_mutex held by this task: */
960 struct rb_root_cached pi_waiters;
961 /* Updated under owner's pi_lock and rq lock */
962 struct task_struct *pi_top_task;
963 /* Deadlock detection and priority inheritance handling: */
964 struct rt_mutex_waiter *pi_blocked_on;
967 #ifdef CONFIG_DEBUG_MUTEXES
968 /* Mutex deadlock detection: */
969 struct mutex_waiter *blocked_on;
972 #ifdef CONFIG_TRACE_IRQFLAGS
973 unsigned int irq_events;
974 unsigned long hardirq_enable_ip;
975 unsigned long hardirq_disable_ip;
976 unsigned int hardirq_enable_event;
977 unsigned int hardirq_disable_event;
978 int hardirqs_enabled;
980 unsigned long softirq_disable_ip;
981 unsigned long softirq_enable_ip;
982 unsigned int softirq_disable_event;
983 unsigned int softirq_enable_event;
984 int softirqs_enabled;
988 #ifdef CONFIG_LOCKDEP
989 # define MAX_LOCK_DEPTH 48UL
992 unsigned int lockdep_recursion;
993 struct held_lock held_locks[MAX_LOCK_DEPTH];
997 unsigned int in_ubsan;
1000 /* Journalling filesystem info: */
1003 /* Stacked block device info: */
1004 struct bio_list *bio_list;
1007 /* Stack plugging: */
1008 struct blk_plug *plug;
1012 struct reclaim_state *reclaim_state;
1014 struct backing_dev_info *backing_dev_info;
1016 struct io_context *io_context;
1018 #ifdef CONFIG_COMPACTION
1019 struct capture_control *capture_control;
1022 unsigned long ptrace_message;
1023 kernel_siginfo_t *last_siginfo;
1025 struct task_io_accounting ioac;
1027 /* Pressure stall state */
1028 unsigned int psi_flags;
1030 #ifdef CONFIG_TASK_XACCT
1031 /* Accumulated RSS usage: */
1033 /* Accumulated virtual memory usage: */
1035 /* stime + utime since last update: */
1038 #ifdef CONFIG_CPUSETS
1039 /* Protected by ->alloc_lock: */
1040 nodemask_t mems_allowed;
1041 /* Seqence number to catch updates: */
1042 seqcount_t mems_allowed_seq;
1043 int cpuset_mem_spread_rotor;
1044 int cpuset_slab_spread_rotor;
1046 #ifdef CONFIG_CGROUPS
1047 /* Control Group info protected by css_set_lock: */
1048 struct css_set __rcu *cgroups;
1049 /* cg_list protected by css_set_lock and tsk->alloc_lock: */
1050 struct list_head cg_list;
1052 #ifdef CONFIG_X86_CPU_RESCTRL
1057 struct robust_list_head __user *robust_list;
1058 #ifdef CONFIG_COMPAT
1059 struct compat_robust_list_head __user *compat_robust_list;
1061 struct list_head pi_state_list;
1062 struct futex_pi_state *pi_state_cache;
1064 #ifdef CONFIG_PERF_EVENTS
1065 struct perf_event_context *perf_event_ctxp[perf_nr_task_contexts];
1066 struct mutex perf_event_mutex;
1067 struct list_head perf_event_list;
1069 #ifdef CONFIG_DEBUG_PREEMPT
1070 unsigned long preempt_disable_ip;
1073 /* Protected by alloc_lock: */
1074 struct mempolicy *mempolicy;
1076 short pref_node_fork;
1078 #ifdef CONFIG_NUMA_BALANCING
1080 unsigned int numa_scan_period;
1081 unsigned int numa_scan_period_max;
1082 int numa_preferred_nid;
1083 unsigned long numa_migrate_retry;
1084 /* Migration stamp: */
1086 u64 last_task_numa_placement;
1087 u64 last_sum_exec_runtime;
1088 struct callback_head numa_work;
1090 struct numa_group *numa_group;
1093 * numa_faults is an array split into four regions:
1094 * faults_memory, faults_cpu, faults_memory_buffer, faults_cpu_buffer
1095 * in this precise order.
1097 * faults_memory: Exponential decaying average of faults on a per-node
1098 * basis. Scheduling placement decisions are made based on these
1099 * counts. The values remain static for the duration of a PTE scan.
1100 * faults_cpu: Track the nodes the process was running on when a NUMA
1101 * hinting fault was incurred.
1102 * faults_memory_buffer and faults_cpu_buffer: Record faults per node
1103 * during the current scan window. When the scan completes, the counts
1104 * in faults_memory and faults_cpu decay and these values are copied.
1106 unsigned long *numa_faults;
1107 unsigned long total_numa_faults;
1110 * numa_faults_locality tracks if faults recorded during the last
1111 * scan window were remote/local or failed to migrate. The task scan
1112 * period is adapted based on the locality of the faults with different
1113 * weights depending on whether they were shared or private faults
1115 unsigned long numa_faults_locality[3];
1117 unsigned long numa_pages_migrated;
1118 #endif /* CONFIG_NUMA_BALANCING */
1121 struct rseq __user *rseq;
1124 * RmW on rseq_event_mask must be performed atomically
1125 * with respect to preemption.
1127 unsigned long rseq_event_mask;
1130 struct tlbflush_unmap_batch tlb_ubc;
1132 struct rcu_head rcu;
1134 /* Cache last used pipe for splice(): */
1135 struct pipe_inode_info *splice_pipe;
1137 struct page_frag task_frag;
1139 #ifdef CONFIG_TASK_DELAY_ACCT
1140 struct task_delay_info *delays;
1143 #ifdef CONFIG_FAULT_INJECTION
1145 unsigned int fail_nth;
1148 * When (nr_dirtied >= nr_dirtied_pause), it's time to call
1149 * balance_dirty_pages() for a dirty throttling pause:
1152 int nr_dirtied_pause;
1153 /* Start of a write-and-pause period: */
1154 unsigned long dirty_paused_when;
1156 #ifdef CONFIG_LATENCYTOP
1157 int latency_record_count;
1158 struct latency_record latency_record[LT_SAVECOUNT];
1161 * Time slack values; these are used to round up poll() and
1162 * select() etc timeout values. These are in nanoseconds.
1165 u64 default_timer_slack_ns;
1168 unsigned int kasan_depth;
1171 #ifdef CONFIG_FUNCTION_GRAPH_TRACER
1172 /* Index of current stored address in ret_stack: */
1176 /* Stack of return addresses for return function tracing: */
1177 struct ftrace_ret_stack *ret_stack;
1179 /* Timestamp for last schedule: */
1180 unsigned long long ftrace_timestamp;
1183 * Number of functions that haven't been traced
1184 * because of depth overrun:
1186 atomic_t trace_overrun;
1188 /* Pause tracing: */
1189 atomic_t tracing_graph_pause;
1192 #ifdef CONFIG_TRACING
1193 /* State flags for use by tracers: */
1194 unsigned long trace;
1196 /* Bitmask and counter of trace recursion: */
1197 unsigned long trace_recursion;
1198 #endif /* CONFIG_TRACING */
1201 /* Coverage collection mode enabled for this task (0 if disabled): */
1202 unsigned int kcov_mode;
1204 /* Size of the kcov_area: */
1205 unsigned int kcov_size;
1207 /* Buffer for coverage collection: */
1210 /* KCOV descriptor wired with this task or NULL: */
1215 struct mem_cgroup *memcg_in_oom;
1216 gfp_t memcg_oom_gfp_mask;
1217 int memcg_oom_order;
1219 /* Number of pages to reclaim on returning to userland: */
1220 unsigned int memcg_nr_pages_over_high;
1222 /* Used by memcontrol for targeted memcg charge: */
1223 struct mem_cgroup *active_memcg;
1226 #ifdef CONFIG_BLK_CGROUP
1227 struct request_queue *throttle_queue;
1230 #ifdef CONFIG_UPROBES
1231 struct uprobe_task *utask;
1233 #if defined(CONFIG_BCACHE) || defined(CONFIG_BCACHE_MODULE)
1234 unsigned int sequential_io;
1235 unsigned int sequential_io_avg;
1237 #ifdef CONFIG_DEBUG_ATOMIC_SLEEP
1238 unsigned long task_state_change;
1240 int pagefault_disabled;
1242 struct task_struct *oom_reaper_list;
1244 #ifdef CONFIG_VMAP_STACK
1245 struct vm_struct *stack_vm_area;
1247 #ifdef CONFIG_THREAD_INFO_IN_TASK
1248 /* A live task holds one reference: */
1249 refcount_t stack_refcount;
1251 #ifdef CONFIG_LIVEPATCH
1254 #ifdef CONFIG_SECURITY
1255 /* Used by LSM modules for access restriction: */
1259 #ifdef CONFIG_GCC_PLUGIN_STACKLEAK
1260 unsigned long lowest_stack;
1261 unsigned long prev_lowest_stack;
1265 * New fields for task_struct should be added above here, so that
1266 * they are included in the randomized portion of task_struct.
1268 randomized_struct_fields_end
1270 /* CPU-specific state of this task: */
1271 struct thread_struct thread;
1274 * WARNING: on x86, 'thread_struct' contains a variable-sized
1275 * structure. It *MUST* be at the end of 'task_struct'.
1277 * Do not put anything below here!
1281 static inline struct pid *task_pid(struct task_struct *task)
1283 return task->thread_pid;
1287 * the helpers to get the task's different pids as they are seen
1288 * from various namespaces
1290 * task_xid_nr() : global id, i.e. the id seen from the init namespace;
1291 * task_xid_vnr() : virtual id, i.e. the id seen from the pid namespace of
1293 * task_xid_nr_ns() : id seen from the ns specified;
1295 * see also pid_nr() etc in include/linux/pid.h
1297 pid_t __task_pid_nr_ns(struct task_struct *task, enum pid_type type, struct pid_namespace *ns);
1299 static inline pid_t task_pid_nr(struct task_struct *tsk)
1304 static inline pid_t task_pid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1306 return __task_pid_nr_ns(tsk, PIDTYPE_PID, ns);
1309 static inline pid_t task_pid_vnr(struct task_struct *tsk)
1311 return __task_pid_nr_ns(tsk, PIDTYPE_PID, NULL);
1315 static inline pid_t task_tgid_nr(struct task_struct *tsk)
1321 * pid_alive - check that a task structure is not stale
1322 * @p: Task structure to be checked.
1324 * Test if a process is not yet dead (at most zombie state)
1325 * If pid_alive fails, then pointers within the task structure
1326 * can be stale and must not be dereferenced.
1328 * Return: 1 if the process is alive. 0 otherwise.
1330 static inline int pid_alive(const struct task_struct *p)
1332 return p->thread_pid != NULL;
1335 static inline pid_t task_pgrp_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1337 return __task_pid_nr_ns(tsk, PIDTYPE_PGID, ns);
1340 static inline pid_t task_pgrp_vnr(struct task_struct *tsk)
1342 return __task_pid_nr_ns(tsk, PIDTYPE_PGID, NULL);
1346 static inline pid_t task_session_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1348 return __task_pid_nr_ns(tsk, PIDTYPE_SID, ns);
1351 static inline pid_t task_session_vnr(struct task_struct *tsk)
1353 return __task_pid_nr_ns(tsk, PIDTYPE_SID, NULL);
1356 static inline pid_t task_tgid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
1358 return __task_pid_nr_ns(tsk, PIDTYPE_TGID, ns);
1361 static inline pid_t task_tgid_vnr(struct task_struct *tsk)
1363 return __task_pid_nr_ns(tsk, PIDTYPE_TGID, NULL);
1366 static inline pid_t task_ppid_nr_ns(const struct task_struct *tsk, struct pid_namespace *ns)
1372 pid = task_tgid_nr_ns(rcu_dereference(tsk->real_parent), ns);
1378 static inline pid_t task_ppid_nr(const struct task_struct *tsk)
1380 return task_ppid_nr_ns(tsk, &init_pid_ns);
1383 /* Obsolete, do not use: */
1384 static inline pid_t task_pgrp_nr(struct task_struct *tsk)
1386 return task_pgrp_nr_ns(tsk, &init_pid_ns);
1389 #define TASK_REPORT_IDLE (TASK_REPORT + 1)
1390 #define TASK_REPORT_MAX (TASK_REPORT_IDLE << 1)
1392 static inline unsigned int task_state_index(struct task_struct *tsk)
1394 unsigned int tsk_state = READ_ONCE(tsk->state);
1395 unsigned int state = (tsk_state | tsk->exit_state) & TASK_REPORT;
1397 BUILD_BUG_ON_NOT_POWER_OF_2(TASK_REPORT_MAX);
1399 if (tsk_state == TASK_IDLE)
1400 state = TASK_REPORT_IDLE;
1405 static inline char task_index_to_char(unsigned int state)
1407 static const char state_char[] = "RSDTtXZPI";
1409 BUILD_BUG_ON(1 + ilog2(TASK_REPORT_MAX) != sizeof(state_char) - 1);
1411 return state_char[state];
1414 static inline char task_state_to_char(struct task_struct *tsk)
1416 return task_index_to_char(task_state_index(tsk));
1420 * is_global_init - check if a task structure is init. Since init
1421 * is free to have sub-threads we need to check tgid.
1422 * @tsk: Task structure to be checked.
1424 * Check if a task structure is the first user space task the kernel created.
1426 * Return: 1 if the task structure is init. 0 otherwise.
1428 static inline int is_global_init(struct task_struct *tsk)
1430 return task_tgid_nr(tsk) == 1;
1433 extern struct pid *cad_pid;
1438 #define PF_IDLE 0x00000002 /* I am an IDLE thread */
1439 #define PF_EXITING 0x00000004 /* Getting shut down */
1440 #define PF_EXITPIDONE 0x00000008 /* PI exit done on shut down */
1441 #define PF_VCPU 0x00000010 /* I'm a virtual CPU */
1442 #define PF_WQ_WORKER 0x00000020 /* I'm a workqueue worker */
1443 #define PF_FORKNOEXEC 0x00000040 /* Forked but didn't exec */
1444 #define PF_MCE_PROCESS 0x00000080 /* Process policy on mce errors */
1445 #define PF_SUPERPRIV 0x00000100 /* Used super-user privileges */
1446 #define PF_DUMPCORE 0x00000200 /* Dumped core */
1447 #define PF_SIGNALED 0x00000400 /* Killed by a signal */
1448 #define PF_MEMALLOC 0x00000800 /* Allocating memory */
1449 #define PF_NPROC_EXCEEDED 0x00001000 /* set_user() noticed that RLIMIT_NPROC was exceeded */
1450 #define PF_USED_MATH 0x00002000 /* If unset the fpu must be initialized before use */
1451 #define PF_USED_ASYNC 0x00004000 /* Used async_schedule*(), used by module init */
1452 #define PF_NOFREEZE 0x00008000 /* This thread should not be frozen */
1453 #define PF_FROZEN 0x00010000 /* Frozen for system suspend */
1454 #define PF_KSWAPD 0x00020000 /* I am kswapd */
1455 #define PF_MEMALLOC_NOFS 0x00040000 /* All allocation requests will inherit GFP_NOFS */
1456 #define PF_MEMALLOC_NOIO 0x00080000 /* All allocation requests will inherit GFP_NOIO */
1457 #define PF_LESS_THROTTLE 0x00100000 /* Throttle me less: I clean memory */
1458 #define PF_KTHREAD 0x00200000 /* I am a kernel thread */
1459 #define PF_RANDOMIZE 0x00400000 /* Randomize virtual address space */
1460 #define PF_SWAPWRITE 0x00800000 /* Allowed to write to swap */
1461 #define PF_MEMSTALL 0x01000000 /* Stalled due to lack of memory */
1462 #define PF_UMH 0x02000000 /* I'm an Usermodehelper process */
1463 #define PF_NO_SETAFFINITY 0x04000000 /* Userland is not allowed to meddle with cpus_mask */
1464 #define PF_MCE_EARLY 0x08000000 /* Early kill for mce process policy */
1465 #define PF_MEMALLOC_NOCMA 0x10000000 /* All allocation request will have _GFP_MOVABLE cleared */
1466 #define PF_FREEZER_SKIP 0x40000000 /* Freezer should not count it as freezable */
1467 #define PF_SUSPEND_TASK 0x80000000 /* This thread called freeze_processes() and should not be frozen */
1470 * Only the _current_ task can read/write to tsk->flags, but other
1471 * tasks can access tsk->flags in readonly mode for example
1472 * with tsk_used_math (like during threaded core dumping).
1473 * There is however an exception to this rule during ptrace
1474 * or during fork: the ptracer task is allowed to write to the
1475 * child->flags of its traced child (same goes for fork, the parent
1476 * can write to the child->flags), because we're guaranteed the
1477 * child is not running and in turn not changing child->flags
1478 * at the same time the parent does it.
1480 #define clear_stopped_child_used_math(child) do { (child)->flags &= ~PF_USED_MATH; } while (0)
1481 #define set_stopped_child_used_math(child) do { (child)->flags |= PF_USED_MATH; } while (0)
1482 #define clear_used_math() clear_stopped_child_used_math(current)
1483 #define set_used_math() set_stopped_child_used_math(current)
1485 #define conditional_stopped_child_used_math(condition, child) \
1486 do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= (condition) ? PF_USED_MATH : 0; } while (0)
1488 #define conditional_used_math(condition) conditional_stopped_child_used_math(condition, current)
1490 #define copy_to_stopped_child_used_math(child) \
1491 do { (child)->flags &= ~PF_USED_MATH, (child)->flags |= current->flags & PF_USED_MATH; } while (0)
1493 /* NOTE: this will return 0 or PF_USED_MATH, it will never return 1 */
1494 #define tsk_used_math(p) ((p)->flags & PF_USED_MATH)
1495 #define used_math() tsk_used_math(current)
1497 static inline bool is_percpu_thread(void)
1500 return (current->flags & PF_NO_SETAFFINITY) &&
1501 (current->nr_cpus_allowed == 1);
1507 /* Per-process atomic flags. */
1508 #define PFA_NO_NEW_PRIVS 0 /* May not gain new privileges. */
1509 #define PFA_SPREAD_PAGE 1 /* Spread page cache over cpuset */
1510 #define PFA_SPREAD_SLAB 2 /* Spread some slab caches over cpuset */
1511 #define PFA_SPEC_SSB_DISABLE 3 /* Speculative Store Bypass disabled */
1512 #define PFA_SPEC_SSB_FORCE_DISABLE 4 /* Speculative Store Bypass force disabled*/
1513 #define PFA_SPEC_IB_DISABLE 5 /* Indirect branch speculation restricted */
1514 #define PFA_SPEC_IB_FORCE_DISABLE 6 /* Indirect branch speculation permanently restricted */
1515 #define PFA_SPEC_SSB_NOEXEC 7 /* Speculative Store Bypass clear on execve() */
1517 #define TASK_PFA_TEST(name, func) \
1518 static inline bool task_##func(struct task_struct *p) \
1519 { return test_bit(PFA_##name, &p->atomic_flags); }
1521 #define TASK_PFA_SET(name, func) \
1522 static inline void task_set_##func(struct task_struct *p) \
1523 { set_bit(PFA_##name, &p->atomic_flags); }
1525 #define TASK_PFA_CLEAR(name, func) \
1526 static inline void task_clear_##func(struct task_struct *p) \
1527 { clear_bit(PFA_##name, &p->atomic_flags); }
1529 TASK_PFA_TEST(NO_NEW_PRIVS, no_new_privs)
1530 TASK_PFA_SET(NO_NEW_PRIVS, no_new_privs)
1532 TASK_PFA_TEST(SPREAD_PAGE, spread_page)
1533 TASK_PFA_SET(SPREAD_PAGE, spread_page)
1534 TASK_PFA_CLEAR(SPREAD_PAGE, spread_page)
1536 TASK_PFA_TEST(SPREAD_SLAB, spread_slab)
1537 TASK_PFA_SET(SPREAD_SLAB, spread_slab)
1538 TASK_PFA_CLEAR(SPREAD_SLAB, spread_slab)
1540 TASK_PFA_TEST(SPEC_SSB_DISABLE, spec_ssb_disable)
1541 TASK_PFA_SET(SPEC_SSB_DISABLE, spec_ssb_disable)
1542 TASK_PFA_CLEAR(SPEC_SSB_DISABLE, spec_ssb_disable)
1544 TASK_PFA_TEST(SPEC_SSB_NOEXEC, spec_ssb_noexec)
1545 TASK_PFA_SET(SPEC_SSB_NOEXEC, spec_ssb_noexec)
1546 TASK_PFA_CLEAR(SPEC_SSB_NOEXEC, spec_ssb_noexec)
1548 TASK_PFA_TEST(SPEC_SSB_FORCE_DISABLE, spec_ssb_force_disable)
1549 TASK_PFA_SET(SPEC_SSB_FORCE_DISABLE, spec_ssb_force_disable)
1551 TASK_PFA_TEST(SPEC_IB_DISABLE, spec_ib_disable)
1552 TASK_PFA_SET(SPEC_IB_DISABLE, spec_ib_disable)
1553 TASK_PFA_CLEAR(SPEC_IB_DISABLE, spec_ib_disable)
1555 TASK_PFA_TEST(SPEC_IB_FORCE_DISABLE, spec_ib_force_disable)
1556 TASK_PFA_SET(SPEC_IB_FORCE_DISABLE, spec_ib_force_disable)
1559 current_restore_flags(unsigned long orig_flags, unsigned long flags)
1561 current->flags &= ~flags;
1562 current->flags |= orig_flags & flags;
1565 extern int cpuset_cpumask_can_shrink(const struct cpumask *cur, const struct cpumask *trial);
1566 extern int task_can_attach(struct task_struct *p, const struct cpumask *cs_cpus_allowed);
1568 extern void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask);
1569 extern int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask);
1571 static inline void do_set_cpus_allowed(struct task_struct *p, const struct cpumask *new_mask)
1574 static inline int set_cpus_allowed_ptr(struct task_struct *p, const struct cpumask *new_mask)
1576 if (!cpumask_test_cpu(0, new_mask))
1582 extern int yield_to(struct task_struct *p, bool preempt);
1583 extern void set_user_nice(struct task_struct *p, long nice);
1584 extern int task_prio(const struct task_struct *p);
1587 * task_nice - return the nice value of a given task.
1588 * @p: the task in question.
1590 * Return: The nice value [ -20 ... 0 ... 19 ].
1592 static inline int task_nice(const struct task_struct *p)
1594 return PRIO_TO_NICE((p)->static_prio);
1597 extern int can_nice(const struct task_struct *p, const int nice);
1598 extern int task_curr(const struct task_struct *p);
1599 extern int idle_cpu(int cpu);
1600 extern int available_idle_cpu(int cpu);
1601 extern int sched_setscheduler(struct task_struct *, int, const struct sched_param *);
1602 extern int sched_setscheduler_nocheck(struct task_struct *, int, const struct sched_param *);
1603 extern int sched_setattr(struct task_struct *, const struct sched_attr *);
1604 extern int sched_setattr_nocheck(struct task_struct *, const struct sched_attr *);
1605 extern struct task_struct *idle_task(int cpu);
1608 * is_idle_task - is the specified task an idle task?
1609 * @p: the task in question.
1611 * Return: 1 if @p is an idle task. 0 otherwise.
1613 static inline bool is_idle_task(const struct task_struct *p)
1615 return !!(p->flags & PF_IDLE);
1618 extern struct task_struct *curr_task(int cpu);
1619 extern void ia64_set_curr_task(int cpu, struct task_struct *p);
1623 union thread_union {
1624 #ifndef CONFIG_ARCH_TASK_STRUCT_ON_STACK
1625 struct task_struct task;
1627 #ifndef CONFIG_THREAD_INFO_IN_TASK
1628 struct thread_info thread_info;
1630 unsigned long stack[THREAD_SIZE/sizeof(long)];
1633 #ifndef CONFIG_THREAD_INFO_IN_TASK
1634 extern struct thread_info init_thread_info;
1637 extern unsigned long init_stack[THREAD_SIZE / sizeof(unsigned long)];
1639 #ifdef CONFIG_THREAD_INFO_IN_TASK
1640 static inline struct thread_info *task_thread_info(struct task_struct *task)
1642 return &task->thread_info;
1644 #elif !defined(__HAVE_THREAD_FUNCTIONS)
1645 # define task_thread_info(task) ((struct thread_info *)(task)->stack)
1649 * find a task by one of its numerical ids
1651 * find_task_by_pid_ns():
1652 * finds a task by its pid in the specified namespace
1653 * find_task_by_vpid():
1654 * finds a task by its virtual pid
1656 * see also find_vpid() etc in include/linux/pid.h
1659 extern struct task_struct *find_task_by_vpid(pid_t nr);
1660 extern struct task_struct *find_task_by_pid_ns(pid_t nr, struct pid_namespace *ns);
1663 * find a task by its virtual pid and get the task struct
1665 extern struct task_struct *find_get_task_by_vpid(pid_t nr);
1667 extern int wake_up_state(struct task_struct *tsk, unsigned int state);
1668 extern int wake_up_process(struct task_struct *tsk);
1669 extern void wake_up_new_task(struct task_struct *tsk);
1672 extern void kick_process(struct task_struct *tsk);
1674 static inline void kick_process(struct task_struct *tsk) { }
1677 extern void __set_task_comm(struct task_struct *tsk, const char *from, bool exec);
1679 static inline void set_task_comm(struct task_struct *tsk, const char *from)
1681 __set_task_comm(tsk, from, false);
1684 extern char *__get_task_comm(char *to, size_t len, struct task_struct *tsk);
1685 #define get_task_comm(buf, tsk) ({ \
1686 BUILD_BUG_ON(sizeof(buf) != TASK_COMM_LEN); \
1687 __get_task_comm(buf, sizeof(buf), tsk); \
1691 void scheduler_ipi(void);
1692 extern unsigned long wait_task_inactive(struct task_struct *, long match_state);
1694 static inline void scheduler_ipi(void) { }
1695 static inline unsigned long wait_task_inactive(struct task_struct *p, long match_state)
1702 * Set thread flags in other task's structures.
1703 * See asm/thread_info.h for TIF_xxxx flags available:
1705 static inline void set_tsk_thread_flag(struct task_struct *tsk, int flag)
1707 set_ti_thread_flag(task_thread_info(tsk), flag);
1710 static inline void clear_tsk_thread_flag(struct task_struct *tsk, int flag)
1712 clear_ti_thread_flag(task_thread_info(tsk), flag);
1715 static inline void update_tsk_thread_flag(struct task_struct *tsk, int flag,
1718 update_ti_thread_flag(task_thread_info(tsk), flag, value);
1721 static inline int test_and_set_tsk_thread_flag(struct task_struct *tsk, int flag)
1723 return test_and_set_ti_thread_flag(task_thread_info(tsk), flag);
1726 static inline int test_and_clear_tsk_thread_flag(struct task_struct *tsk, int flag)
1728 return test_and_clear_ti_thread_flag(task_thread_info(tsk), flag);
1731 static inline int test_tsk_thread_flag(struct task_struct *tsk, int flag)
1733 return test_ti_thread_flag(task_thread_info(tsk), flag);
1736 static inline void set_tsk_need_resched(struct task_struct *tsk)
1738 set_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
1741 static inline void clear_tsk_need_resched(struct task_struct *tsk)
1743 clear_tsk_thread_flag(tsk,TIF_NEED_RESCHED);
1746 static inline int test_tsk_need_resched(struct task_struct *tsk)
1748 return unlikely(test_tsk_thread_flag(tsk,TIF_NEED_RESCHED));
1752 * cond_resched() and cond_resched_lock(): latency reduction via
1753 * explicit rescheduling in places that are safe. The return
1754 * value indicates whether a reschedule was done in fact.
1755 * cond_resched_lock() will drop the spinlock before scheduling,
1757 #ifndef CONFIG_PREEMPT
1758 extern int _cond_resched(void);
1760 static inline int _cond_resched(void) { return 0; }
1763 #define cond_resched() ({ \
1764 ___might_sleep(__FILE__, __LINE__, 0); \
1768 extern int __cond_resched_lock(spinlock_t *lock);
1770 #define cond_resched_lock(lock) ({ \
1771 ___might_sleep(__FILE__, __LINE__, PREEMPT_LOCK_OFFSET);\
1772 __cond_resched_lock(lock); \
1775 static inline void cond_resched_rcu(void)
1777 #if defined(CONFIG_DEBUG_ATOMIC_SLEEP) || !defined(CONFIG_PREEMPT_RCU)
1785 * Does a critical section need to be broken due to another
1786 * task waiting?: (technically does not depend on CONFIG_PREEMPT,
1787 * but a general need for low latency)
1789 static inline int spin_needbreak(spinlock_t *lock)
1791 #ifdef CONFIG_PREEMPT
1792 return spin_is_contended(lock);
1798 static __always_inline bool need_resched(void)
1800 return unlikely(tif_need_resched());
1804 * Wrappers for p->thread_info->cpu access. No-op on UP.
1808 static inline unsigned int task_cpu(const struct task_struct *p)
1810 #ifdef CONFIG_THREAD_INFO_IN_TASK
1811 return READ_ONCE(p->cpu);
1813 return READ_ONCE(task_thread_info(p)->cpu);
1817 extern void set_task_cpu(struct task_struct *p, unsigned int cpu);
1821 static inline unsigned int task_cpu(const struct task_struct *p)
1826 static inline void set_task_cpu(struct task_struct *p, unsigned int cpu)
1830 #endif /* CONFIG_SMP */
1833 * In order to reduce various lock holder preemption latencies provide an
1834 * interface to see if a vCPU is currently running or not.
1836 * This allows us to terminate optimistic spin loops and block, analogous to
1837 * the native optimistic spin heuristic of testing if the lock owner task is
1840 #ifndef vcpu_is_preempted
1841 # define vcpu_is_preempted(cpu) false
1844 extern long sched_setaffinity(pid_t pid, const struct cpumask *new_mask);
1845 extern long sched_getaffinity(pid_t pid, struct cpumask *mask);
1847 #ifndef TASK_SIZE_OF
1848 #define TASK_SIZE_OF(tsk) TASK_SIZE
1854 * Map the event mask on the user-space ABI enum rseq_cs_flags
1855 * for direct mask checks.
1857 enum rseq_event_mask_bits {
1858 RSEQ_EVENT_PREEMPT_BIT = RSEQ_CS_FLAG_NO_RESTART_ON_PREEMPT_BIT,
1859 RSEQ_EVENT_SIGNAL_BIT = RSEQ_CS_FLAG_NO_RESTART_ON_SIGNAL_BIT,
1860 RSEQ_EVENT_MIGRATE_BIT = RSEQ_CS_FLAG_NO_RESTART_ON_MIGRATE_BIT,
1863 enum rseq_event_mask {
1864 RSEQ_EVENT_PREEMPT = (1U << RSEQ_EVENT_PREEMPT_BIT),
1865 RSEQ_EVENT_SIGNAL = (1U << RSEQ_EVENT_SIGNAL_BIT),
1866 RSEQ_EVENT_MIGRATE = (1U << RSEQ_EVENT_MIGRATE_BIT),
1869 static inline void rseq_set_notify_resume(struct task_struct *t)
1872 set_tsk_thread_flag(t, TIF_NOTIFY_RESUME);
1875 void __rseq_handle_notify_resume(struct ksignal *sig, struct pt_regs *regs);
1877 static inline void rseq_handle_notify_resume(struct ksignal *ksig,
1878 struct pt_regs *regs)
1881 __rseq_handle_notify_resume(ksig, regs);
1884 static inline void rseq_signal_deliver(struct ksignal *ksig,
1885 struct pt_regs *regs)
1888 __set_bit(RSEQ_EVENT_SIGNAL_BIT, ¤t->rseq_event_mask);
1890 rseq_handle_notify_resume(ksig, regs);
1893 /* rseq_preempt() requires preemption to be disabled. */
1894 static inline void rseq_preempt(struct task_struct *t)
1896 __set_bit(RSEQ_EVENT_PREEMPT_BIT, &t->rseq_event_mask);
1897 rseq_set_notify_resume(t);
1900 /* rseq_migrate() requires preemption to be disabled. */
1901 static inline void rseq_migrate(struct task_struct *t)
1903 __set_bit(RSEQ_EVENT_MIGRATE_BIT, &t->rseq_event_mask);
1904 rseq_set_notify_resume(t);
1908 * If parent process has a registered restartable sequences area, the
1909 * child inherits. Only applies when forking a process, not a thread.
1911 static inline void rseq_fork(struct task_struct *t, unsigned long clone_flags)
1913 if (clone_flags & CLONE_THREAD) {
1916 t->rseq_event_mask = 0;
1918 t->rseq = current->rseq;
1919 t->rseq_sig = current->rseq_sig;
1920 t->rseq_event_mask = current->rseq_event_mask;
1924 static inline void rseq_execve(struct task_struct *t)
1928 t->rseq_event_mask = 0;
1933 static inline void rseq_set_notify_resume(struct task_struct *t)
1936 static inline void rseq_handle_notify_resume(struct ksignal *ksig,
1937 struct pt_regs *regs)
1940 static inline void rseq_signal_deliver(struct ksignal *ksig,
1941 struct pt_regs *regs)
1944 static inline void rseq_preempt(struct task_struct *t)
1947 static inline void rseq_migrate(struct task_struct *t)
1950 static inline void rseq_fork(struct task_struct *t, unsigned long clone_flags)
1953 static inline void rseq_execve(struct task_struct *t)
1959 void __exit_umh(struct task_struct *tsk);
1961 static inline void exit_umh(struct task_struct *tsk)
1963 if (unlikely(tsk->flags & PF_UMH))
1967 #ifdef CONFIG_DEBUG_RSEQ
1969 void rseq_syscall(struct pt_regs *regs);
1973 static inline void rseq_syscall(struct pt_regs *regs)
1979 const struct sched_avg *sched_trace_cfs_rq_avg(struct cfs_rq *cfs_rq);
1980 char *sched_trace_cfs_rq_path(struct cfs_rq *cfs_rq, char *str, int len);
1981 int sched_trace_cfs_rq_cpu(struct cfs_rq *cfs_rq);
1983 const struct sched_avg *sched_trace_rq_avg_rt(struct rq *rq);
1984 const struct sched_avg *sched_trace_rq_avg_dl(struct rq *rq);
1985 const struct sched_avg *sched_trace_rq_avg_irq(struct rq *rq);
1987 int sched_trace_rq_cpu(struct rq *rq);
1989 const struct cpumask *sched_trace_rd_span(struct root_domain *rd);